Breast cancer is a massive and scary topic, and it's normal to have a ton of questions. Here's a list of some of the most frequently asked questions we get about breast cancer. Don't see your question on the list? Let us know what you're curious about, and we'll do our best to answer it.

The Answers:Is it true that one in eight women will get breast cancer?
Not exactly. The one-in-eight statistic doesn't accurately reflect the average woman's breast cancer risk. Age is the most important risk factor for breast cancer. That means the older a woman is, the greater her risk of developing the disease. Statistics from the U.S. National Cancer Institute show that a woman's chance of being diagnosed with breast cancer by age is:

"Ever" is lifetime risk. This means a woman has a one-in-eight chance of getting breast cancer after the age of 70. SOURCE: Susan Love, M.D., president of the Dr. Susan Love Research Foundation

Is it necessary to do a monthly breast self-exam?
Breast self-exam (BSE) has been widely hailed as a technique that can help women find breast cancer early—with the implication that finding it early will save lives. There's just one problem: No study ever has found that BSE reduces breast cancer deaths. That's why after many years of supporting BSE, the American Cancer Society, in May 2003, revised its breast cancer screening guidelines and now calls BSE optional.

Many women do find their cancers themselves. But very few find them while doing BSE. More typically, the woman just rolled over in bed, or felt a lump while soaping up in the shower, or had it pointed out by a lover.

This is why it's important for women to become acquainted with their breasts, to know what they look like, and to know what lumps and bumps are normal for them. (It's best to do this soaped up in the shower or bath.) But there's a crucial difference between getting acquainted with your breasts and BSE. BSE is like a search-and-destroy mission. It often makes women tense. And it's all about trying to find cancer. In contrast, getting acquainted with your breasts gives you a good, integrated sense of your body, which will help you know when something doesn't feel right. Some women like to do BSE, and that's fine. But no one should be made to feel guilty for not doing it—especially if they are well acquainted with their breasts.SOURCE: Susan Love, M.D., president of the Dr. Susan Love Research Foundation

Do most women die of breast cancer?
Women fear breast cancer more than any other disease. And many people believe that most women die of breast cancer. But that's not the case. In the U.S., breast cancer is the fifth-leading cause of death for women. Heart disease is first.

The American Cancer Society estimates that in 2010, 207,000 women will be diagnosed with invasive breast cancer and that 40,000 will die of the disease.

When should I start having mammograms, and how often should I have them?
Everyone agrees that women age 50 and older should have mammograms. But there has been quite a controversy for a number of years now as to whether women between the ages of 40 and 49 should also have annual mammograms. The problem is that women between 40 and 49 typically still have dense breasts, and on a mammogram, this dense breast tissue shows up as white—which is the same color that cancer appears as on a mammogram. With menopause, which typically begins around age 50, the dense tissue in women's breasts is replaced with fatty tissue, which looks gray on a mammogram. It is much easier to see the white cancer against this gray background, which is why mammography works better on women aged 50 and older.

To date, eight randomized controlled trials have found that mammography screening for women between 40 and 49 has no effect on mortality. Even so, some health organizations continue to recommend annual mammography for women between the ages of 40 and 49. At first glance, there would seem to be little harm in this recommendation. But there is a downside. Many abnormalities seen on mammograms may not be cancer (these are called false positives), but they will prompt additional testing and anxiety. In fact, as many as three out of 10 women who begin annual screening at age 40 will have an abnormal mammogram during the next decade, and the majority of these will end up having biopsies—only to learn that the test was a false positive.

The bottom line: Even in older women, mammography is far from a perfect screening tool. It may help you find your cancer early, but finding a cancer "early" is not a guarantee that your life will be saved. New data suggest that there are different types of cancers and that how quickly a cancer progresses has more to do with the type of cancer it is than when it is found. Probably the best way to decide when you should begin having mammograms is to discuss your personal risk factors for breast cancer with your physician.SOURCE: Susan Love, M.D., president of the Dr. Susan Love Research Foundation

If no one in my family has had breast cancer, can I still get it?
Yes, you can. When women learn that breast cancer can be a genetic disease, they often think this means it is a disease that must be inherited. But that's not the case. A genetic disease is one that is caused by a genetic mutation that is either inherited or arises spontaneously. Only about 30 percent of the women who develop breast cancer have a family history of the disease. The other 70 percent have what is called a "sporadic occurrence." This means there is no known family history of the disease.SOURCE: Susan Love, M.D., president of the Dr. Susan Love Research Foundation

What does breast density have to do with breast cancer?
Breast density has to do with the tissue in your breasts and how that shows up on a mammogram. But while you can’t feel this out on your own, you might find out about it at your next screening: Many states have adopted breast density notification laws, which require physicians to inform a patient if they have dense breasts, according to a new report in the journal Radiology.

So why should you care about how dense your set is? There are two main reasons, says Debra Ikeda, M.D., professor of radiology at Stanford School of Medicine. “There’s an association between dense breast tissue and a slightly higher risk of having breast cancer,” says Ikeda. It's worth noting, though, that this association is much smaller than any genetic risk factor. “The second problem is that of masking,” says Ikeda. This is what happens when dense breast tissue shows up as white on a mammogram, making it harder to spot cancer (which also shows up white). However, studies have shown that this is less of an issue in digital mammograms as opposed to film screen mammograms.

But don’t freak out if you see this new language on your mammography report. While researchers seem pretty divided on the issue, having dense breast tissue doesn’t necessarily mean you need additional tests—especially since roughly half of all women have dense breasts. It’s simply something to keep in mind and to discuss with your doctor—along with any other risk factors you may have, says Ikeda. Click here for more information on breast density.

How does your weight influence your breast cancer risk?
It's the one thing most doctors agree on: If you can do only one thing to lower your lifetime risk, it should be maintaining a healthy weight. Packing too many pounds can increase your breast-cancer chances by 30 to 60 percent, says Carolyn Aldigé, of the Prevent Cancer Foundation. (Particularly worrisome is often-hidden abdominal fat, which on its own can raise your risk by 43 percent.)

See, fat cells don't just sit still; they can pump out extra estrogen, says Karen M. Basen-Engquist, Ph.D., M.P.H., of the University of Texas MD Anderson Cancer Center. So the more fat cells you have, the more estrogen is likely coursing through your body. And the more of that circulating estrogen you have over the course of your life, the higher your breast-cancer risk, says Graham Colditz, M.D., Ph.D., of the Institute for Public Health at the Washington University in St. Louis School of Medicine.

Plus, being overweight or obese means you're providing a host environment for cancer progression, says Lee W. Jones, Ph.D., of the Duke Cancer Institute. "That's lots of insulin, lots of glucose, lots of inflammation—all of which conspire to speed up cancer-cell growth once a malignancy occurs."

What does stress have to do with breast cancer?
Being permanently frazzled can steer you toward risk-boosting behaviors such as smoking, drinking, or overeating. But research suggests long-term stress might open an even bigger door to breast cancer by increasing blood flow to tumors, triggering hormones that encourage tumor growth, and sending your body into a state of constant inflammation. Need yet one more reason to chill? Chronic stress may increase the growth and spread of one of the most deadly forms of breast cancer—"triple negative"—for which there is no proven treatment. Click here for 3 ways to cut your stress levels.